Disclaimer: Any advice or information presented here is the opinion of the Author. It is not FAA approved or acceptable data, nor is it an authorization to perform maintenance or determine airworthiness.
In advising owners and operators on the 12 year “thing”, I’m surprised to hear them say that “no other aircraft or engine requires this crap”. That is untrue. Many other aircraft and engines will require some type of calendar overhaul. These aircraft tend to be turbine powered aircraft. Often they are the kind of aircraft that are used more commercially or as VIP transport for corporations or private owners. So, yes, in relation to an old Cessna which does not have a calendar overhaul requirement, a Robinson does seem like the manufacturer is imposing their rule over you unfairly. Does everyone know that Lycoming also recommends overhaul of their engines at 12 years in Service Instruction 1009? Current revision as of this writing is SI 1009BB. Which is funny because it states overhaul at 12 years, and then states for part 91 operations and EASA NCO operations that an appropriately rated mechanic may extend the TBO. However, it warranted enough thought and research from Lycoming to recommend the 12 year mark for overhaul.
To be clear, I personally don’t have a horse in this race. It would not be possible for me to care less whether or not owners or operators do or not do the 12 year. My purpose here as always is just to bring up the topic and open the conversation. Also, this posting does not really apply to part 135 operators. They have an ops spec that is essentially their own set of FAR’s and it will be customized to their operation. This issue tends to arise more with private owners, flight schools’ and some of the other operators that conduct commercial operations under part 91 maintenance requirements.
Sorry folks, the water is going to get much more cloudy before it gets clear. Now, in the case of the R44 we have a couple things going on. As promised in my bio, I’ll put out what I consider to be FACTS: (if these are wrong, please correct me)
- The R44 was certified under 27 for normal category rotorcraft. Type Certificate number H11NM. FAR 27 Appendix A requires aircraft manufacturers to produce Instructions for Continued Airworthiness as part of certification. Appendix A to Part 27
- The 2 R44 engines ( O-540, IO-540 ) were certified under CAR regulations, so they were to have a manual, however, the manual did not have to be one document. It is accepted practice that the entirety of Lycoming Service Letters, Service Instructions, Service Bulletins and the Operators Handbook comprise the “manual” for pre-maintenance manual Lycomings.
- FAR 43.16 States:
Each person performing an inspection or other maintenance specified in an Airworthiness Limitations section of a manufacturer’s maintenance manual or Instructions for Continued Airworthiness shall perform the inspection or other maintenance in accordance with that section, or in accordance with operations specifications approved by the Administrator under part 121 or 135, or an inspection program approved under §91.409(e).
- FAR 43.15 (b) states:
(b) Rotorcraft. Each person performing an inspection required by Part 91 on a rotorcraft shall inspect the following systems in accordance with the maintenance manual or Instructions for Continued Airworthiness of the manufacturer concerned:
(1) The drive shafts or similar systems.
(2) The main rotor transmission gear box for obvious defects.
(3) The main rotor and center section (or the equivalent area).
(4) The auxiliary rotor on helicopters.
- FAR 91.403 (c) states:
(c) No person may operate an aircraft for which a manufacturer’s maintenance manual or instructions for continued airworthiness has been issued that contains an airworthiness limitations section unless the mandatory replacement times, inspection intervals, and related procedures specified in that section or alternative inspection intervals and related procedures set forth in an operations specification approved by the Administrator under part 121 or 135 of this chapter or in accordance with an inspection program approved under §91.409(e) have been complied with.
- The Robinson R44 Maintenance Manual is the manual and the ICA (instructions for continued airworthiness) for the R44 series aircraft required by certification.
Ok, with me so far? Near as I can tell, it’s a veeeeeeerrrrrrryyyyy grey area to say that an owner is not is legally required to perform the 12 year limited overhaul as listed in R44 Manual Chapter 2. Let’s break it down a couple ways and see if we can get past this and still feel good about ourselves as aviators. I’ll caveat here and say that yes, as an IA, I have returned one aircraft to service that was beyond it’s 12 year, it had newer main and tail rotor blades as well. However, I did make a phone call to the local FSDO and discuss this prior to doing it. To be honest, I never really felt great about that. I felt just a little dirty and was glad when the aircraft was overhauled shortly after annual.
From the perspective of a part 91 operator who presumably has main and tail rotor blades that are within their 12 year life. Yes, one could possibly squeeze by without doing a 12 year if you read 43.15 VERY critically and ONLY use Robinson’s checklist excepting the parts that talk about overhaul limits. Furthermore, you COULD possibly then read 43.16 very critically and use the legalese logic that you are not performing an inspection specified in Robinson’s airworthiness limitations, but instead are performing an inspection specified by 91.409. As far as I can tell, this isn’t much to go on as a reason to fly beyond 12 years, but it’s about all anyone has got in this example.
Another FAR maze you could try to run on this problem is to use the accepted standard practice that FAR’s and AD’s are regulatory, but Service Bulletins, Letter, Instructions, and manuals are just manufacturers opinion, and yes, you would also be “correct” based on accepted practice that is sanctioned by FAA inspectors. Or would you be “correct?” I don’t know the FAR’s (laws) state pretty clearly that ICA’s and manuals are to be published as part of certification, and that those same documents are to be used on rotorcraft as part of the performance rules. Now, maybe as an IA your inspector is lenient on this and understands that some areas are grey and it’s impossible to comply with every rule. However, in my opinion that’s a risky little game to play. The truth of the matter is that as an IA you are given the authority to make an airworthiness decision and by making the aircraft airworthy past 12 years, you are walking pretty far out on a lonely plank. Odds are that it won’t be an issue, but what happens if the aircraft goes down and you have to explain how you forged ahead in the face of the rules we all operate under. It’s going to be pretty hard to pass that omission off as a simple mistake. As an owner you could get yourself backed into the corner of either A – Not being able to get an annual, or B – Thinking you are all aiworthy and good to go based what could be construed to be some fairly shaky logic and getting into trouble should you ever need to make an insurance claim, depending on your insurer.
In either of these circumstances the potential for financial and legal issues goes well beyond my personal risk tolerance level. As an IA who strives to provide good service and advice to my clients, I could not in good faith sign an annual inspection unless I had cleared the way with the FAA and their insurance / financing companies. And then, in that case, I am myself exposed to possible certificate action if there is an issue. What’s the point?
A 12 year inspection isn’t insanely expensive if planned for and executed properly. Even tearing the engine down and performing the Lycoming overhaul process as well as sending components back to Robinson for 12 year inspection or outright overhaul can be effected for a good price by a reputable A&P. Here’s the catch, just like anything it will cost an arm and a leg, and be a half-assed job if executed without educating oneself on the process, researching the best options for each and every part, and then going forward without a plan. If you drop it off at the maintenance hangar and your mechanic just gets to ripping and tearing it apart it will cost you.
I would STRONGLY recommend to all who are involved in Robinson hell’s that are beyond the airframe 12 year mark to evaluate your position very carefully. Again, I am not passing judgement, I am only opening the conversation. These are a great aircraft and I’m sure that thousands of them would safely fly for decades without being taken apart. But there are others that are in rough environments, or have been misused, or left to sit out on the ramp that probably warrant a nice spa treatment and reset to continue flying safely.
Keep the whirly bits up – Johnny